With development of mobile Internet and popularity of intelligent terminals, data traffic increases rapidly. A wireless local area network (WLAN) has become one of mainstream mobile broadband access technologies due to advantages of high rate and low costs.
In an existing wireless local area network system, a station sends and receives data by using a contention mechanism. When the station obtains a resource by means of contention, other stations cannot send or receive data, thereby causing resource wastes. To ensure high resource usage, a scheduling-based transmission mode is used in an existing orthogonal frequency division multiple access (OFDMA) system. In this mode, the station does not need to contend for a channel to obtain a transmission opportunity; instead, an access point allocates a physical time frequency resource, and indicates to each station independently. For example, in the existing OFDMA system, a channel resource is divided into multiple resource blocks, and the access point independently indicates to each station according to a start position and an end position of a resource allocated to the station, causing large signaling overheads during resource allocation.